I have a Dell Optiplex 780 pc that came with an Intel Core 2 Duo processor, 1TB hardrive, and 8gb of ram. I know nothing about PC hardware and would like to get the most powerful processor and graphics card I can for this pc without making any other major changes to it. I'd like to be able to play some basic steam games on the highest quality possible for this pc. I hear the Core 2 Quad 3ghz is good but have no idea on how to install a new card.